New mathematical diffusion models for solid state homogenization of dendrite segregation were presented to calculate the concentration evolution of alloying elements during solid-state homogenization of dendrite segregation in any cross section of a three-dimensional dendrite system. With mathematical accumulation, all the individual concentration profiles of every dendrite can be accumulated to form a concentration equation, which may be required by sine model or not. Then diffusion homogenization processes for any cross sections of dendrites in solid state can be calculated from the equation. The only assumption of the new models was that any individual concentration profile in a dendrite system could be simulated by Gauss equation of Fick-2 law. New mathematical diffusion models for solid state homogenization of dendrite segregation were presented to calculate the concentration evolution of alloying elements during solid-state homogenization of dendrite segregation in any cross section of a three-dimensional dendrite system. With mathematical accumulation, all the individual concentration profiles of every dendrite can be accumulated to form a concentration equation, which may be required by sine model or not. Then diffusion homogenization processes for any cross sections of dendrites in solid state can be calculated from the equation. The only assumption of the new models was that any individual concentration profile in a dendrite system could be simulated by Gauss equation of Fick-2 law.